Segment and Geographic Information - Schedule of Net Sales to External Customers and Location of Net Plant, Equipment and Timberlands (Detail) - USD ($) $ in Thousands	3 Months Ended								12 Months Ended
	Dec. 31, 2019	Sep. 30, 2019	Jun. 30, 2019	Mar. 31, 2019	Dec. 31, 2018	Sep. 30, 2018	Jun. 30, 2018	Mar. 31, 2018	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017
Revenues from External Customers and Long-Lived Assets [Line Items]
Net sales	$ 230,972	$ 232,515	$ 235,053	$ 229,133	$ 229,480	$ 209,855	$ 215,742	$ 211,209	$ 927,673	$ 866,286	$ 800,362
Plant, Equipment and Timberlands – Net	537,421				556,044				537,421	556,044	515,183
United States [Member]
Revenues from External Customers and Long-Lived Assets [Line Items]
Net sales									167,887	124,690	89,773
Plant, Equipment and Timberlands – Net	105,763				109,797				105,763	109,797	105,663
Germany [Member]
Revenues from External Customers and Long-Lived Assets [Line Items]
Net sales									504,012	483,628	450,668
Plant, Equipment and Timberlands – Net	274,146				286,839				274,146	286,839	240,932
United Kingdom [Member]
Revenues from External Customers and Long-Lived Assets [Line Items]
Net sales									70,018	76,053	76,594
Plant, Equipment and Timberlands – Net	52,039				50,483				52,039	50,483	55,494
Canada [Member]
Revenues from External Customers and Long-Lived Assets [Line Items]
Net sales									121,789	114,877	120,433
Plant, Equipment and Timberlands – Net	72,436				74,448				72,436	74,448	78,220
Other [Member]
Revenues from External Customers and Long-Lived Assets [Line Items]
Net sales									63,967	67,038	62,894
Plant, Equipment and Timberlands – Net	$ 33,037				$ 34,477				$ 33,037	$ 34,477	$ 34,874